1. Technical Field
The present disclosure relates to methods for making current collectors and methods for making electrodes of electrochemical batteries having the current collectors.
2. Description of Related Art
Current collector is an important part in an electrochemical battery. The current collector is used for supporting electrode active material and providing an electron transfer route between the electrode active material and an outside circuit. Therefore, a performance of the current collector affects a performance of the electrochemical battery.
Conventional current collectors usually are metal sheets, plates, or foils, such as copper foils and aluminum foils. However, the metal sheets are easily to be oxidized to form a passive film or corroded by an electrolyte solvent of the electrochemical battery to form an insulating layer on the surface thereof. The passive film or insulating layer greatly increases a contact resistance between the electrode active material and the metal foil, thereby decreasing a discharge capacity and capacity retention of the electrochemical battery. A layer of graphene is formed on the surface of the current collector to improve the performance of the current collector by dispersing graphene powder, in a solvent, to form a graphene solution first and then coating and drying the graphene solution on the surface of the metal foil. However, this method needs a high uniformity of the dispersing and a high uniformity of the coating related to complicated processes, which are difficult to be compatible with the present electrochemical battery manufacture industry.
What is needed, therefore, is to provide a method for making a current collector and a method for making an electrode of an electrochemical battery having the current collector, which are efficiency to improve the discharge capacity and capacity retention, and simple and compatible with the present electrochemical battery manufacture industry.